Numerical Simulation Methods Applied at Fiber Grating Sensors Design

Abstract

The paper presents the results obtained in simulation of fiber Bragg grating (FBG) and long-period grating (LPG) sensors and their applications. The optical properties of FBG and LPG are firstly analyzed and, consequently, the basics of simulation models are provided. Coupled-mode theory and the transfer matrix methods are the two techniques used for the simulation of FBG and LPG. The numerical simulations are performed for an improved design of these types of fiber sensors, designs dedicated to specified applications. The different FBG types, i.e. the normal, chirped, apodized, according to different laws and tilted cases, are analyzed. Also, various LPG configurations are numerically simulated. The two main categories of sensing applications, for temperature and for mechanical stress/strain evaluation, are simulated for each type of fiber grating sensor. The chapter is intended to be a synthesis of already obtained results to which some results of research in development are added.